HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

Well, bison kit applied.

I have the neo magnet off one of the tweeters. Cant get to plastidip the front of the metal dome because of a metal grille (like a microphone grille). Is it ok to plastidip the back of the metal dome ?

Pictures to follow when tinypics gets its act together.

I don't know you are in your own experiment, on your own!

Tinypics are shit - wont upload today for some reason. Had to host them elsewhere.

Picture of the doped 5" mid/bass. Look like fried eggs - good enough to eat although the smell is toxic



The inside of the cabs - need to remove the mdf strengthening which sticks out all way around the inside of the cab (half way between baffle and back). That will allow more steel to go in.



Do you think I have enough Bison kit ?



Picture of the inside of the metal dome tweeter. I should think I could plastidip this but assume I should avoid getting it on the voicecoil ?



The crossover - not going to be used



The very small neo magnet



The tweeter assembly removed from inside the cab




This is going to be a steep learning curve but fun I hope . Not sure yet if I have enough doping in the mid/ bass. The tweeter is going to be an arse to do if I have to mask off the voicecoil. Will have to see if I can gain entry to the front of the metal dome.

Plastidip is synthetic rubber so an insulator, so no problem on the voice coil apart from it will cut down on its ability to ventilate heat, but on a tweeter that should be no problem, but a no-no on a bass unit voice coil.

The other thing is not very much as if it touches both side of the gap the coil wont move.

Ok, cheers for that doc. I will try and mask the voicecoil off with masking tape and give the inside a thin coat of plastidip.

I will probably plastidip the mid/bass cone as well when I have got the amount of doping right. No nasty reactions with the cone material.....yet.

Will leave it for a week to dry before listening.

Copied from somewhere on the net.

"To achieve their distinguished sonic performance, both models utilize a newly developed 6 -1/2 -inch CPC™ (Continuous Profile Cone) aluminum mid/bass driver with a heavy -duty long -throw voice coil and proprietary one -inch aluminum dome tweeter -both designed and developed in -house in conjunction with extensive critical listening evaluations. The Continuous Profile Cone driver technology features a smooth, seamless concave surface, to provide controlled movement at low frequencies and virtually eliminate unwanted cone breakup modes at higher frequencies for ultra -fast transient response and wide dynamic range along with exceptionally low coloration."

Apparently, CPC stands for 'continuous profile cone' and so the cone is probably just aluminium, not a mix of metals as DQ thought.

Whether I should believe the rest of the marketing I don't know. From what I remember they did sound ok if a bit harsh.

You're doing great work Stu.

antonio66 wrote: ↑Tue Aug 08, 2017 1:45 pm You're doing great work Stu.

Thanks. It is a huge learning process for me. With my Marantz Imperial 7 (still not finished ) I bought all the drivers from the doc so that was all done for me. With this I thought I would have a go at the actual doping. If it all goes wrong then I will just buy some more of the docs ready doped units and a couple of Visaton G20 tweeters. That will entail some bodging of the cabinets though and I have had more than enough of that with the Marantz 7's.

Half an hour with a small battery operated chainsaw, a wood chisel & a hammer produced this



The strengthening ring succumbed to removal. It was glued in a shallow rebate. Chainsaw (yes a chainsaw) was used to cut as near as I dared to the cabinet walls leaving the ring in small sections which were easily removed with a wood chisel. The corner blocks also came out quite easily with the wood chisel.

Should take the steel I have in mind for this project. The sides are going to be a little tricky as there is not much room to get the driver in. Might have to do two plates with a small gap in between them so the widest part of the driver can go in.

Steady hands and a with a chainsaw, but well done.